Report the system double-click interval

wsap_term hardcodes 400 ms in three places to count clicks.

yasl_display_double_click_ms() reads the interval from the system. X11
parses Net/DoubleClickTime from the XSETTINGS owner's property. Wayland
has no protocol for it, so it asks the Settings portal for KDE's
DoubleClickInterval, which KDE sends as a string and which exists only
when the user set it, then GNOME's double-click. X11 without XSETTINGS
asks the portal too. Cocoa reads NSEvent.doubleClickInterval. Missing or
implausible values give YASL_DOUBLE_CLICK_MS_DEFAULT, 400 ms.

The X11 state test covers the XSETTINGS parser in both byte orders and
with truncation. The Xwayland test owns the settings selection. The
desktop test serves both portal keys. The Cocoa path is not built or run
here.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 32 insertions, 0 deletions

diff --git a/tests/x11/test_input.c b/tests/x11/test_input.c
index bbcbf45..95943d1 100644
--- a/tests/x11/test_input.c
+++ b/tests/x11/test_input.c
@@ -65,6 +65,37 @@ static void check_selection_encoding(struct x11_display *d, struct x11_surface *
     }
 }
 
+/* Own the XSETTINGS selection with one Net/DoubleClickTime value. */
+static void check_double_click(struct x11_display *d)
+{
+    /* No settings owner and no portal: the default applies. */
+    unsetenv("DBUS_SESSION_BUS_ADDRESS");
+    unsetenv("XDG_RUNTIME_DIR");
+    assert(yasl_display_double_click_ms(&d->base) == YASL_DOUBLE_CLICK_MS_DEFAULT);
+
+    char name[32];
+    snprintf(name, sizeof(name), "_XSETTINGS_S%d", d->screen);
+    Atom selection = XInternAtom(d->native, name, False);
+    Atom property = XInternAtom(d->native, "_XSETTINGS_SETTINGS", False);
+    Window owner = XCreateSimpleWindow(d->native, DefaultRootWindow(d->native),
+        0, 0, 1, 1, 0, 0, 0);
+    XSetSelectionOwner(d->native, selection, owner, CurrentTime);
+    static const unsigned char blob[] = {
+        LSBFirst, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0,
+        0, 0, 19, 0, 'N', 'e', 't', '/', 'D', 'o', 'u', 'b', 'l', 'e',
+        'C', 'l', 'i', 'c', 'k', 'T', 'i', 'm', 'e', 0, 0, 0, 0, 0,
+        250, 0, 0, 0,
+    };
+    XChangeProperty(d->native, owner, property, property, 8, PropModeReplace,
+        blob, sizeof(blob));
+    XSync(d->native, False);
+    assert(yasl_display_double_click_ms(&d->base) == 250);
+
+    XDestroyWindow(d->native, owner);
+    XSync(d->native, False);
+    assert(yasl_display_double_click_ms(&d->base) == YASL_DOUBLE_CLICK_MS_DEFAULT);
+}
+
 int main(void)
 {
     struct yasl_display_spec ds = {.backend = YASL_BACKEND_X11};
@@ -117,6 +148,7 @@ int main(void)
     XFree(saved);
     s->ic = saved_ic;
     check_selection_encoding(d, s);
+    check_double_click(d);
 
     /* Test CSD interactive actions, window menu, and IME caret */
     assert(yasl_display_caps(base) & YASL_CAP_CSD);